I fly a lot for my job. I always dread seeing they booked me with Delta. I understand about weather delays. And the occasional mechanical issues. I boarded a plane at JFK and it was over 100 degrees on it. They said that it would cool down once they started the engines. We backed away from the gate were told we were cleared for take off. We taxied for a bit then stopped. We sat on the run way for 50 min before the pilot came on and said that we were delayed due to weather. I boarded this plane at 2:15. It is now 5:00 and weare still on a the runway in a plane that is now at 90 drgrees. Who knows when we will even take off. Every time I fly they are always canceling or reverting flights. Every trip there is an. I must say I would rather fly with anyone other than delta. Bad job!